initial commit for billing branch.

add account button, pointing to /account
in user menu, remove messages (ok, warning), only leave error
Add the logic deciding what to show on enable monitoring
fix typo
some unfinished UI billing enhancements
remove error in backends
added purchase option
Merge branch 'billing' of https://github.com/mistio/mist.io into billing
remove or
improve enable monitoring mechanism
resolve merge
added back button on monitoring popup
remove extra closing div
fix user dialog height
change expired to has_expired
fix free-trial appearing on expired plan
dialogs for enable monitoring
fix broken main.css
add back button to plan select popup
styling enable trial plan dialog
submit trial plan and set as Mist.current_plan